离子色谱-柱切换法测定土壤浸出液中的氟离子

摘要

A new method was proposed for the determination of fluoride in soil water extract by ion chromatography with column-switching technique. A reversed-phase column was used as a pretreatment column on-line to separate fluoride and organic acids as well as to eliminate organics. Fluoride was collected by a collection loop and delivered to the analytical system. Under the optimum conditions,the linear range of the method for fluoride was 0. 05-10. 0 mg/L (r=0. 999 9),and the limit of detection(S/N=3)was 5. 50 μg/L. The recovery was in the range of 103. 4%-105. 3% with the relative standard deviation of 2. 0%-2. 1%. The method could be applied to determine fluoride in complicated samples.%建立了离子色谱-柱切换测定土壤浸出液中氟离子的方法。使用柱切换技术，将样品通过高聚物反相色谱柱进行在线预处理，分离氟离子和小分子有机酸，同时除去水溶性有机杂质，采用收集环收集氟离子并进入分析系统分析，消除了测定氟离子时普遍存在的干扰问题。分析系统的淋洗液为 KOH溶液，流速为1.0 mL／min，采用抑制性电导检测，外标法定量。氟离子的线性范围为0.05～10.0 mg／L，相关系数为0.9999，加标回收率为103.4％～105.3％，相对标准偏差为2.0％～2.1％，检出限（S／N＝3）为5.50μg／L。该方法适用于测定复杂基体样品中的氟离子。